Giuseppe
Emeritus
[Source: PLoS ONE, full page: (LINK). Abstract, edited.]
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Intense Co-Circulation of Non-Influenza Respiratory Viruses during the First Wave of Pandemic Influenza pH1N1/2009: A Cohort Study in Reunion Island
Herv? Pascalis<SUP>1</SUP><SUP>,</SUP><SUP>2</SUP><SUP>#</SUP>, Sarah Temmam<SUP>1</SUP><SUP>,</SUP><SUP>4</SUP><SUP>#</SUP>, Magali Turpin<SUP>1</SUP><SUP>,</SUP><SUP>2</SUP>, Olivier Rollot<SUP>3</SUP>, Antoine Flahault<SUP>7</SUP>, Fabrice Carrat<SUP>6</SUP>, Xavier de Lamballerie<SUP>5</SUP>, Patrick G?rardin<SUP>3</SUP>, Koussay Dellagi<SUP>1</SUP><SUP>,</SUP><SUP>2</SUP><SUP>*</SUP>
<SUP></SUP>
1 Centre de Recherche et de Veille sur les maladies ?mergentes dans l?Oc?an Indien (CRVOI), Sainte-Clotilde, La R?union, France, 2 Institut de Recherche pour le D?veloppement (IRD), Sainte-Clotilde, La R?union, France, 3 Centre d?Investigation Clinique-Epid?miologie Clinique (CIC-EC), (INSERM/CHR/Universit?/URMLR), Centre Hospitalier R?gional, Saint-Pierre, La R?union, France, 4 Ecologie microbienne (UMR 5557) CNRS-Universit? de Claude Bernard, Lyon, France, 5 Unit? des Virus Emergents (UMR-S 190), IRD-Universit? de la M?diterran?e, Marseille, France, 6 Epid?miologie des Maladies Infectieuses et Mod?lisation (UMR-S 707), INSERM-Universit? Pierre et Marie Curie, Paris, France, 7 Ecole des Hautes Etudes en Sant? Publique, EHESP, Rennes, France
Abstract
Objective
The aim of the present study was to weigh up, at the community level, the respective roles played by pandemic Influenza (pH1N1) virus and co-circulating human Non-Influenza Respiratory Viruses (NIRVs) during the first wave of the 2009 pH1N1 pandemic.
Methods
A population-based prospective cohort study was conducted in Reunion Island during the austral winter 2009 (weeks 30?44) that allowed identification of 125 households with at least one member who developed symptoms of Influenza-like illness (ILI). Three consecutive nasal swabs were collected from each household member (443 individuals) on day 0, 3 and 8 post-ILI report and tested for pH1N1 and 15 NIRVs by RT-PCR.
Results
Two successive waves of viral infections were identified: a first wave (W33?37) when pH1N1 was dominant and co-circulated with NIRVs, sharply interrupted by a second wave (W38?44), almost exclusively composed of NIRVs, mainly human Rhinoviruses (hRV) and Coronaviruses (hCoV). Data suggest that some interference may occur between NIRVs and pH1N1 when they co-circulate within the same household, where NIRVs were more likely to infect pH1N1 negative individuals than pH1N1 positive peers (relative risk: 3.13, 95% CI: 1.80?5.46, P<0.001). Viral shedding was significantly shorter (P = 0.035) in patients who were co-infected by pH1N1 and NIRV or by two different NIRVs compared to those who were infected with only one virus, whatever this virus was (pH1N1 or NIRVs). Although intense co-circulation of NIRVs (especially hRV) likely brought pH1N1 under the detection threshold, it did not prevent spread of the pandemic Influenza virus within the susceptible population nor induction of an extensive herd immunity to it.
Conclusion
Our results suggest that NIRV co-infections during Influenza epidemics may act as cofactors that contribute to shape an outbreak and modulate the attack rate. They further warrant broad spectrum studies to fully understand viral epidemics.
Citation: Pascalis H, Temmam S, Turpin M, Rollot O, Flahault A, et al. (2012) Intense Co-Circulation of Non-Influenza Respiratory Viruses during the First Wave of Pandemic Influenza pH1N1/2009: A Cohort Study in Reunion Island. PLoS ONE 7(9): e44755. doi:10.1371/journal.pone.0044755
Editor: Krzysztof Pyrc, Faculty of Biochemistry Biophysics and Biotechnology, Jagiellonian University, Poland
Received: May 10, 2012; Accepted: August 7, 2012; Published: September 12, 2012
Copyright: ? 2012 Pascalis et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: This study was supported by funds from CPER-ERDF (Contrat Programme Etat-Region and European Regional Development Fund), INSERM/IMMI (L?Institut de Microbiologie et des Maladies Infectieuses) and CRVOI (The Centre for Research and Intelligence on Emerging Diseases in the Indian Ocean). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing interests: The authors have declared that no competing interests exist.
* E-mail: koussay.dellagi@ird.fr
# These authors contributed equally to this work.
-Herv? Pascalis<SUP>1</SUP><SUP>,</SUP><SUP>2</SUP><SUP>#</SUP>, Sarah Temmam<SUP>1</SUP><SUP>,</SUP><SUP>4</SUP><SUP>#</SUP>, Magali Turpin<SUP>1</SUP><SUP>,</SUP><SUP>2</SUP>, Olivier Rollot<SUP>3</SUP>, Antoine Flahault<SUP>7</SUP>, Fabrice Carrat<SUP>6</SUP>, Xavier de Lamballerie<SUP>5</SUP>, Patrick G?rardin<SUP>3</SUP>, Koussay Dellagi<SUP>1</SUP><SUP>,</SUP><SUP>2</SUP><SUP>*</SUP>
<SUP></SUP>
1 Centre de Recherche et de Veille sur les maladies ?mergentes dans l?Oc?an Indien (CRVOI), Sainte-Clotilde, La R?union, France, 2 Institut de Recherche pour le D?veloppement (IRD), Sainte-Clotilde, La R?union, France, 3 Centre d?Investigation Clinique-Epid?miologie Clinique (CIC-EC), (INSERM/CHR/Universit?/URMLR), Centre Hospitalier R?gional, Saint-Pierre, La R?union, France, 4 Ecologie microbienne (UMR 5557) CNRS-Universit? de Claude Bernard, Lyon, France, 5 Unit? des Virus Emergents (UMR-S 190), IRD-Universit? de la M?diterran?e, Marseille, France, 6 Epid?miologie des Maladies Infectieuses et Mod?lisation (UMR-S 707), INSERM-Universit? Pierre et Marie Curie, Paris, France, 7 Ecole des Hautes Etudes en Sant? Publique, EHESP, Rennes, France
Abstract
Objective
The aim of the present study was to weigh up, at the community level, the respective roles played by pandemic Influenza (pH1N1) virus and co-circulating human Non-Influenza Respiratory Viruses (NIRVs) during the first wave of the 2009 pH1N1 pandemic.
Methods
A population-based prospective cohort study was conducted in Reunion Island during the austral winter 2009 (weeks 30?44) that allowed identification of 125 households with at least one member who developed symptoms of Influenza-like illness (ILI). Three consecutive nasal swabs were collected from each household member (443 individuals) on day 0, 3 and 8 post-ILI report and tested for pH1N1 and 15 NIRVs by RT-PCR.
Results
Two successive waves of viral infections were identified: a first wave (W33?37) when pH1N1 was dominant and co-circulated with NIRVs, sharply interrupted by a second wave (W38?44), almost exclusively composed of NIRVs, mainly human Rhinoviruses (hRV) and Coronaviruses (hCoV). Data suggest that some interference may occur between NIRVs and pH1N1 when they co-circulate within the same household, where NIRVs were more likely to infect pH1N1 negative individuals than pH1N1 positive peers (relative risk: 3.13, 95% CI: 1.80?5.46, P<0.001). Viral shedding was significantly shorter (P = 0.035) in patients who were co-infected by pH1N1 and NIRV or by two different NIRVs compared to those who were infected with only one virus, whatever this virus was (pH1N1 or NIRVs). Although intense co-circulation of NIRVs (especially hRV) likely brought pH1N1 under the detection threshold, it did not prevent spread of the pandemic Influenza virus within the susceptible population nor induction of an extensive herd immunity to it.
Conclusion
Our results suggest that NIRV co-infections during Influenza epidemics may act as cofactors that contribute to shape an outbreak and modulate the attack rate. They further warrant broad spectrum studies to fully understand viral epidemics.
Citation: Pascalis H, Temmam S, Turpin M, Rollot O, Flahault A, et al. (2012) Intense Co-Circulation of Non-Influenza Respiratory Viruses during the First Wave of Pandemic Influenza pH1N1/2009: A Cohort Study in Reunion Island. PLoS ONE 7(9): e44755. doi:10.1371/journal.pone.0044755
Editor: Krzysztof Pyrc, Faculty of Biochemistry Biophysics and Biotechnology, Jagiellonian University, Poland
Received: May 10, 2012; Accepted: August 7, 2012; Published: September 12, 2012
Copyright: ? 2012 Pascalis et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: This study was supported by funds from CPER-ERDF (Contrat Programme Etat-Region and European Regional Development Fund), INSERM/IMMI (L?Institut de Microbiologie et des Maladies Infectieuses) and CRVOI (The Centre for Research and Intelligence on Emerging Diseases in the Indian Ocean). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing interests: The authors have declared that no competing interests exist.
* E-mail: koussay.dellagi@ird.fr
# These authors contributed equally to this work.
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